The Controlled Atmosphere Cone Calorimeter: A Literature Review

Cone calorimeters are widely used to assess heat release parameters and flammability of combustible materials, but their use is limited for applications where the global equivalence ratio (GER) exceeds one, because they can only replicate burning in open conditions. The standardisation of the controlled atmosphere cone calorimeter (CACC) in the ISO/TS 5660-5:2020 offers an opportunity to investigate the potential advantages and limitations of this apparatus. This paper presents a detailed review of existing studies conducted using the CACC. The review is aimed at examining the importance of atmospheric control for bench-scale experimental methods and the research-based development of key features of the apparatus. In addition, it highlights the research yet to be carried out to optimise the use of CACC as a tool in fire science. The effects of various design parameters are discussed including the method used for GER control, the chimney, the chamber, the gas inflow rate and others. Despite standardisation, it is concluded that there is limited consensus on optimal CACC control variables. A lack of consensus has led to significantly different testing conditions even where researchers use the same materials and have similar research objectives. The lack of best
practice, particularly with regards to a gas sampling location and the method of GER control, motivates the need for further research so as to improve the value of data collected, reduce uncertainty and optimise CACC reproducibility.